A10 Networks (ATEN) 10-Q 8 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Registrant Name	A10 Networks, Inc.
Entity Central Index Key	0001580808
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		78,986,601
Entity Current Reporting Status	Yes
Entity Shell Company	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 65,633	$ 45,742
Marketable securities	77,273	84,180
Accounts receivable, net of allowances of $267 and $52, respectively	42,862	53,566
Inventory	20,764	22,384
Prepaid expenses and other current assets	12,518	15,067
Total current assets	219,050	220,939
Property and equipment, net	7,462	7,656
Goodwill	1,307	1,307
Intangible assets	1,944	2,305
Other non-current assets	40,294	41,846
Total assets	270,057	274,053
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable	3,937	7,592
Accrued liabilities	24,243	27,756
Deferred revenue	62,718	62,233
Total current liabilities	90,898	97,581
Deferred revenue, non-current	38,560	38,931
Other non-current liabilities	27,347	28,754
Total liabilities	156,805	165,266
Commitments and contingencies (Note 2 and Note 5)
Stockholders' equity:
Common stock, $0.00001 par value: 500,000 shares authorized; 78,710 and 77,580 shares issued and outstanding, respectively	1	1
Additional paid-in-capital	403,650	398,600
Accumulated other comprehensive income (loss)	(37)	251
Accumulated deficit	(290,362)	(290,065)
Total stockholders' equity	113,252	108,787
Total liabilities and stockholders' equity	$ 270,057	$ 274,053

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 267	$ 52
Common Stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	78,710,000	77,580,000
Common stock, shares outstanding (in shares)	78,710,000	77,580,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Total revenue	$ 53,764	$ 50,290
Cost of revenue:
Total cost of revenue	12,142	12,250
Gross profit	41,622	38,040
Operating expenses:
Sales and marketing	20,621	24,483
Research and development	15,315	16,166
General and administrative	5,895	8,358
Total operating expenses	41,831	49,007
Loss from operations	(209)	(10,967)
Non-operating income (expense):
Interest expense	0	(155)
Interest and other income (expense), net	231	(633)
Total non-operating income (expense), net	231	(788)
Income (loss) before provision for income taxes	22	(11,755)
Provision for income taxes	319	517
Net loss	$ (297)	$ (12,272)
Net loss per share:
Basic (in dollars per share)	$ 0	$ (0.16)
Diluted (in dollars per share)	$ 0	$ (0.16)
Weighted-average shares used in computing net loss per share:
Basic (in shares)	78,061	74,809
Diluted (in shares)	78,061	74,809
Products
Revenue:
Total revenue	$ 30,736	$ 28,230
Cost of revenue:
Total cost of revenue	6,941	7,516
Services
Revenue:
Total revenue	23,028	22,060
Cost of revenue:
Total cost of revenue	$ 5,201	$ 4,734

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (297)	$ (12,272)
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on marketable securities	(288)	240
Comprehensive loss	$ (585)	$ (12,032)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued (in shares)		$ 1
Beginning balance at Dec. 31, 2018		$ 103,883	$ 376,272	$ (144)	$ (272,246)
Beginning balance (in shares) at Dec. 31, 2018		74,301
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee equity incentive plans (in shares)		882
Common stock issued under employee equity incentive plans		$ 0	1,027
Stock-based compensation			3,896
Unrealized gain (loss) on marketable securities	$ 240			240
Net loss	(12,272)				(12,272)
Ending balance (in shares) at Mar. 31, 2019		75,183
Ending balance at Mar. 31, 2019	96,774		381,195	96	(284,518)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued (in shares)		$ 1
Common stock issued (in shares)	1	1
Beginning balance at Dec. 31, 2019	108,787	$ 108,787	398,600	251	(290,065)
Beginning balance (in shares) at Dec. 31, 2019		77,580
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee equity incentive plans (in shares)		1,130
Common stock issued under employee equity incentive plans		$ 0	2,005
Stock-based compensation			3,045
Unrealized gain (loss) on marketable securities	(288)			(288)
Net loss	(297)				(297)
Ending balance (in shares) at Mar. 31, 2020		78,710
Ending balance at Mar. 31, 2020	113,252		$ 403,650	$ (37)	$ (290,362)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued (in shares)	$ 1	$ 1

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (297)	$ (12,272)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	3,311	2,447
Stock-based compensation	3,040	3,896
Other non-cash items	(13)	(246)
Changes in operating assets and liabilities:
Accounts receivable	10,767	9,285
Inventory	1,472	(3,325)
Prepaid expenses and other assets	2,426	(2,409)
Accounts payable	(3,718)	(492)
Accrued and other liabilities	(4,919)	(3,616)
Deferred revenue	114	603
Other	0	71
Net cash provided by (used in) operating activities	12,183	(6,058)
Cash flows from investing activities:
Proceeds from sales of marketable securities	1,914	8,674
Proceeds from maturities of marketable securities	10,175	4,500
Purchases of marketable securities	(5,518)	(13,859)
Purchases of property and equipment	(868)	(936)
Net cash provided by (used in) investing activities	5,703	(1,621)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee equity incentive plans	2,005	1,027
Other	0	(2)
Net cash provided by financing activities	2,005	1,025
Net increase (decrease) in cash and cash equivalents	19,891	(6,654)
Cash and cash equivalents - beginning of period	45,742	40,621
Cash and cash equivalents - end of period	65,633	33,967
Non-cash investing and financing activities:
Inventory transfers to property and equipment	149	303
Purchases of property and equipment included in accounts payable	$ 63	$ 485

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Description of Business A10 Networks, Inc. (together with our subsidiaries, the “Company”, “we”, “our” or “us”) was incorporated in California in 2004 and reincorporated in Delaware in March 2014. We are headquartered in San Jose, California and have wholly-owned subsidiaries throughout the world including Asia and Europe. We are a leading provider of secure application solutions and services that enable a new generation of intelligently connected companies with the ability to continuously improve cyber protection and digital responsiveness across dynamic Information Technology (“IT”) and network infrastructures. Our portfolio of software and hardware solutions combines industry-leading performance and scale with advanced intelligent automation, machine learning, data driven analytics, and threat intelligence to ensure security and availability of customer applications across their multi-cloud and mobile infrastructure networks, including on-premise, private and public clouds. As the cyber threat landscape intensifies and network architectures evolve, we are committed to providing customers with greater connected intelligence to improve the security, visibility, automation, availability, flexibility, management and performance of their applications. Our customers include leading cloud providers, web-scale businesses, service providers, government organizations and enterprises. Our product portfolio seeks to address many of the aforementioned challenges and solution requirements. The portfolio consists of six secure application solutions; Thunder Application Delivery Controller (“ADC”), Lightning Application Delivery Controller (“Lightning ADC”), Thunder Carrier Grade Networking (“CGN”), Thunder Threat Protection System (“TPS”), Thunder SSL Insight (“SSLi”) and Thunder Convergent Firewall (“CFW”) and intelligent management, and automation tools; Harmony Controller and aGalaxy TPS. Our products are offered in a variety of form factors and payment models, including physical appliances and perpetual and subscription based software licenses, as well as pay-as-you-go licensing models and FlexPool, a flexible consumption-based software model. Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of A10 Networks, Inc. and its subsidiaries after elimination of all intercompany accounts and transactions. We have prepared the accompanying unaudited condensed consolidated financial statements pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC” or the “Commission”). As permitted under these rules and regulations, we have condensed or omitted certain financial information and footnote disclosures we normally include in our annual consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The unaudited condensed consolidated balance sheet as of December 31, 2019 has been derived from our audited financial statements, which are included in our 2019 Annual Report on Form 10-K for the year ended December 31, 2019 on file with the SEC (the “2019 Annual Report”). These financial statements have been prepared on the same basis as our annual financial statements and, in management’s opinion, reflect all adjustments consisting only of normal recurring adjustments that are necessary for a fair presentation of our financial information. Our interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the financial statements and accompanying notes thereto in the 2019 Annual Report. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Those estimates and assumptions affect revenue recognition and deferred revenue, the allowance for doubtful accounts, the sales return reserve, the valuation of inventory, the fair value of marketable securities, contingencies and litigation, accrued liabilities, deferred commissions and the determination of fair value of stock-based compensation. These estimates are based on information available as of the date of the condensed consolidated financial statements. Due to the COVID-19 pandemic, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of May 8, 2020, the date of issuance of this Quarterly Report on Form 10-Q. These estimates may change, as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions. Significant Accounting Policies The Company’s significant accounting policies are disclosed in Part II-Item 8, “Financial Statements and Supplementary Data,” of the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 filed with the SEC on March 10, 2020, except for the Company’s capitalization of internally developed software expenses which is described below. There have been no other material changes to the Company’s significant accounting policies during the three months ended March 31, 2020 . Capitalization of Internally Developed Software to be Marketed and Sold The Company began capitalizing software engineering labor costs related to certain long-term projects that are expected to take more than a year to complete. The Company accounts for the capitalization of labor costs under ASC Topic 985-20 - Software to be Sold, Leased or Marketed . During the three months ended March 31, 2020, the Company’s capitalized labor costs were not material. Concentration of Credit Risk and Significant Customers Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents, marketable securities and accounts receivable. Our cash, cash equivalents and marketable securities are held and invested in high-credit quality financial instruments by recognized financial institutions and are subject to minimum credit risk. Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing periodic credit evaluations based on a number of factors, including past transaction experience, evaluation of credit history and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. Significant customers, including distribution channel partners and direct customers, are those which represent 10% or more of our total revenue for each period presented or our gross accounts receivable balance as of each respective balance sheet date. Revenues from our significant customers as a percentage of our total revenue are as follows: Three Months Ended Customers 2020 2019 Customer A (a distribution channel partner) * 13% Customer B (a distribution channel partner) 17% * Customer C (a distribution channel partner) 16% * * represents less than 10% of total revenue As of March 31, 2020 , two customers accounted for 21% and 20% , respectively, of our total gross accounts receivable. As of December 31, 2019 , two customers accounted for 17% and 12% , respectively, of our total gross accounts receivable. Recent Adopted Accounting Pronouncements Effective January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), as amended, using a modified retrospective approach, with certain exceptions allowed. The standard amends the guidance for measuring and recording credit losses on financial assets measured at amortized cost by replacing the incurred-loss model with an expected-loss model. This new standard also requires that credit losses related to available-for-sale debt securities be recorded as an allowance through net income rather than by reducing the carrying amount under the current, other-than-temporary-impairment model. The adoption of ASU 2016-13 did not have a significant impact on the Company’s Condensed Consolidated Financial Statements. Effective January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820 - Changes to the Disclosure Requirements for the Fair Value Measurement) . Entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The guidance is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The new guidance did not have a significant impact on the Company’s Condensed Consolidated Financial Statements. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350)—Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 simplifies the accounting for goodwill impairments by eliminating the requirement to compare the implied fair value of goodwill with its carrying amount as part of step two of the goodwill impairment test referenced in Accounting Standards Codification (“ASC”) 350, Intangibles - Goodwill and Other (“ASC 350”). As a result, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value. However, the impairment loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 is effective for annual reporting periods beginning after December 15, 2019, including any interim impairment tests within those annual periods, with early application permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. In January 2020, the Company adopted ASU 2017-04, and the adoption had no impact on our condensed consolidated financial statements. The Company will perform future goodwill impairment tests according to ASU 2017-04.

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	Leases We lease various operating spaces in the United States, Asia and Europe under non-cancellable operating lease arrangements that expire on various dates through July 2027. These arrangements require us to pay certain operating expenses, such as taxes, repairs and insurance, and contain renewal and escalation clauses. The table below presents the Company’s right-of-use assets and lease liabilities as of March 31, 2020 (in thousands): March 31, 2020 Operating leases Right-of-use assets: Other non-current assets $ 31,340 Total right-of-use assets $ 31,340 Lease liabilities: Accrued liabilities $ 4,716 Other non-current liabilities 26,871 Total operating lease liabilities $ 31,587 The aggregate future lease payments for non-cancelable operating leases as of March 31, 2020 were as follows (in thousands): Remainder of 2020 $ 4,230 2021 5,519 2022 4,659 2023 4,414 2024 4,518 Thereafter 11,773 Total lease payments 35,113 Less: imputed interest (3,526 ) Present value of lease liabilities $ 31,587 The components of lease costs were as follows (in thousands): Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Operating lease costs $ 1,777 $ 893 Short-term lease costs 158 137 Total lease costs $ 1,935 $ 1,030 Average lease terms and discount rates for the Company’s operating leases were as follows (in thousands): March 31, 2020 Weighted-average remaining term (years) 6.87 Weighted-average discount rate 3.14 % Supplemental cash flow information for the Company’s operating leases was as follows (in thousands): Three Months Ended March 31, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,665 No new operating leases were entered into during the three months ended March 31, 2020 .

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	Marketable Securities and Fair Value Measurements Marketable Securities Marketable securities, classified as available-for-sale, consisted of the following (in thousands): March 31, 2020 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 9,049 $ 6 $ — $ 9,055 $ 10,548 $ 10 $ — $ 10,558 Corporate securities 51,041 53 (163 ) 50,931 51,745 207 (1 ) 51,951 U.S. Treasury and agency securities 6,716 64 — 6,780 9,222 3 — 9,225 Commercial paper 500 — — 500 500 — — 500 Asset-backed securities 10,003 16 (12 ) 10,007 11,914 32 — 11,946 Total $ 77,309 $ 139 $ (175 ) $ 77,273 $ 83,929 $ 252 $ (1 ) $ 84,180 During the three months ended March 31, 2020 and 2019 , we did not reclassify any amount to earnings from accumulated other comprehensive income (loss) related to unrealized gains or losses. The following table summarizes the cost and estimated fair value of marketable securities based on stated effective maturities as of March 31, 2020 (in thousands): Amortized Cost Fair Value Less than 1 year $ 34,906 $ 34,902 Mature in 1 - 3 years 42,403 42,371 Total $ 77,309 $ 77,273 All available-for-sale securities have been classified as current because they are available for use in current operations. Marketable securities in an unrealized loss position consisted of the following (in thousands): Less Than 12 Months 12 Months or More Total March 31, 2020 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Certificates of deposit $ — $ — $ 2,375 $ (1 ) $ 2,375 $ (1 ) Corporate securities 15,751 (68 ) 13,359 (94 ) 29,110 (162 ) Asset-backed securities 1,372 (2 ) 3,045 (10 ) 4,417 (12 ) Total $ 17,123 $ (70 ) $ 18,779 $ (105 ) $ 35,902 $ (175 ) Less Than 12 Months 12 Months or More Total December 31, 2019 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate securities $ 2,996 $ (1 ) $ — $ — $ 2,996 $ (1 ) Based on evaluation of securities that have been in a continuous loss position, we did not recognize any other-than-temporary impairment charges during the three months ended March 31, 2020 and 2019 . Fair Value Measurements The following is a summary of our cash, cash equivalents and marketable securities measured at fair value on a recurring basis (in thousands): March 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 48,175 $ — $ — $ 48,175 $ 35,546 $ — $ — $ 35,546 Cash equivalents 17,458 — — 17,458 10,196 — — 10,196 Certificates of deposit — 9,055 — 9,055 — 10,558 — 10,558 Corporate securities — 50,931 — 50,931 — 51,951 — 51,951 U.S. Treasury and agency securities — 6,780 — 6,780 — 9,225 — 9,225 Commercial paper — 500 — 500 — 500 — 500 Asset-backed securities — 10,007 — 10,007 — 11,946 — 11,946 Total $ 65,633 $ 77,273 $ — $ 142,906 $ 45,742 $ 84,180 $ — $ 129,922 There were no transfers between Level 1 and Level 2 fair value measurement categories during the three months ended March 31, 2020 and 2019 .

Condensed Consolidated Financia

Condensed Consolidated Financial Statement Details	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Condensed Consolidated Financial Statement Details	Condensed Consolidated Financial Statement Details Inventory Inventory consisted of the following (in thousands): March 31, December 31, Raw materials $ 9,829 $ 9,495 Finished goods 10,935 12,889 Total inventory $ 20,764 $ 22,384 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): March 31, 2020 December 31, 2019 Prepaid expenses $ 4,514 $ 6,163 Deferred contract acquisition costs 5,302 6,231 Other 2,702 2,673 Total prepaid expenses and other current assets $ 12,518 $ 15,067 Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): Useful Life March 31, December 31, (in years) Equipment 1 - 5 $ 23,483 $ 22,702 Software 1 - 3 765 726 Furniture and fixtures 1 - 7 652 459 Leasehold improvements Lease term 5,438 5,440 Construction in process 48 — Property and equipment, gross 30,386 29,327 Less: accumulated depreciation (22,924 ) (21,671 ) Property and equipment, net $ 7,462 $ 7,656 Depreciation expense on property and equipment was $1.3 million and $1.2 million for the three months ended March 31, 2020 and 2019 , respectively. Intangible Assets Purchased intangible assets, net, consisted of the following (in thousands): March 31, 2020 December 31, 2019 Cost Accumulated Amortization Net Cost Accumulated Amortization Net Developed technology $ 5,050 $ (3,788 ) $ 1,262 $ 5,050 $ (3,535 ) $ 1,515 Patents 2,936 (2,254 ) $ 682 2,936 (2,146 ) 790 Total intangible assets $ 7,986 $ (6,042 ) $ 1,944 $ 7,986 $ (5,681 ) $ 2,305 Amortization expense related to purchased intangible assets was $0.4 million for the three months ended March 31, 2020 and 2019 , respectively. Future amortization expense for purchased intangible assets as of March 31, 2020 is as follows (in thousands): Fiscal Year Remainder of 2020 $ 1,082 2021 862 Total $ 1,944 Accrued Liabilities Accrued liabilities consisted of the following (in thousands): March 31, December 31, Accrued compensation and benefits $ 10,121 $ 12,227 Accrued tax liabilities 2,987 4,354 Lease liability 4,716 5,109 Other 6,419 6,066 Total accrued liabilities $ 24,243 $ 27,756 Deferred Revenue Deferred revenue consisted of the following (in thousands): March 31, December 31, Deferred revenue: Products $ 6,456 $ 6,593 Services 94,822 94,571 Total deferred revenue 101,278 101,164 Less: current portion (62,718 ) (62,233 ) Non-current portion $ 38,560 $ 38,931

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments We lease various operating spaces in the United States, Asia and Europe under non-cancelable operating lease arrangements that expire on various dates through July 2027. These arrangements require us to pay certain operating expenses, such as taxes, repairs and insurance, and contain renewal and escalation clauses. We recognize rent expense under these arrangements on a straight-line basis over the term of the lease. See Note 2 - Leases for the Company’s aggregate future lease payments for the Company’s non-cancelable operating leases as of March 31, 2020 . Rent expense was $1.6 million and $1.0 million for three months ended March 31, 2020 and 2019, respectively. Purchase Commitments We have open purchase commitments with third-party contract manufacturers with facilities in Taiwan to supply nearly all of our finished goods inventories, spare parts, and accessories. These purchase orders are expected to be paid within one year of the issuance date. Guarantees and Indemnifications In the normal course of business, we provide indemnifications to customers against claims of intellectual property infringement made by third parties arising from the use of our products. Other guarantees or indemnification arrangements include guarantees of product and service performance, and standby letters of credit for lease facilities and corporate credit cards. We have not recorded a liability related to these indemnification and guarantee provisions and our guarantees and indemnification arrangements have not had any significant impact on our consolidated financial statements to date.

Equity Incentive Plans and Stoc

Equity Incentive Plans and Stock-Based Compensation	3 Months Ended
	Mar. 31, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans and Stock-Based Compensation	Equity Incentive Plans and Stock-Based Compensation Equity Incentive Plans 2014 Equity Incentive Plan The 2014 Equity Incentive Plan (the “2014 Plan”) provides for the granting of stock options, restricted stock awards, restricted stock units (“RSUs”), performance-based RSUs (“PSUs”), stock appreciation rights, performance units and performance shares to our employees, consultants and members of our Board of Directors. The shares authorized for the 2014 Plan increase annually by the lesser of (i) 8,000,000 shares, (ii) 5% of the outstanding shares of common stock on the last day of our immediately preceding fiscal year, or (iii) such other amount as determined by our Board of Directors. Accordingly, effective January 1, 2020 , the number of shares in the 2014 Plan increased by 3,879,002 shares, representing 5% of the prior year end’s common stock outstanding. As of March 31, 2020 , we had 15,166,550 shares available for future grant under the 2014 Plan. 2014 Employee Stock Purchase Plan In October 2018, the Board of Directors approved amending the 2014 Purchase Plan (the “Amended 2014 Purchase Plan”) in order to, among other things, reduce the maximum contribution participants can make under the plan from 15% to 10% of eligible compensation. The Amended 2014 Purchase Plan also reflects revised offering periods, which were changed from 24 months to six months in duration and that begin on or about December 1 and June 1 each year, starting in December 2018. As of March 31, 2020 , the Company had 2,402,820 shares available for future issuance under the Amended 2014 Purchase Plan. Stock-Based Compensation A summary of our stock-based compensation expense is as follows (in thousands): Three Months Ended March 31, 2020 2019 Stock-based compensation by type of award: Stock options $ 110 $ 184 Stock awards 2,682 3,474 Employee stock purchase rights 248 238 $ 3,040 $ 3,896 Stock-based compensation by category of expense: Cost of revenue $ 325 $ 324 Sales and marketing 764 1,321 Research and development 1,006 1,331 General and administrative 945 920 $ 3,040 $ 3,896 As of March 31, 2020 , the Company had $24.3 million of unrecognized stock-based compensation expense related to unvested stock-based awards which will be recognized over a weighted-average period of 2.64 years. Stock Options The following tables summarize our stock option activities and related information: Number of Shares (thousands) Weighted-Average Exercise Price per Share Weighted-Average Remaining Contractual Term (years) Aggregate Intrinsic Value (thousands) Outstanding as of December 31, 2019 3,702 $ 5.57 Granted — — Exercised (644 ) 4.37 Canceled (171 ) 6.29 Outstanding as of March 31, 2020 2,887 5.80 3.01 $ 3,195 Vested and exercisable as of March 31, 2020 2,810 $ 5.73 2.90 $ 3,194 As of March 31, 2020 , the aggregate intrinsic value represents the excess of the closing price of our common stock of $6.21 over the exercise price of the outstanding in-the-money options. The intrinsic value of options exercised was $1.2 million and $1.1 million during the three months ended March 31, 2020 and 2019 , respectively. Stock Awards We have granted RSUs to our employees, consultants and members of our Board of Directors, and PSUs to certain executives. In February 2016, we granted 547,000 PSUs with certain financial and operational targets. Actual performance, as measured at the time and prior to the restatement of the 2016 financial statements, resulted in participants achieving 80% of target. Given the PSUs did not contain explicit or implicit claw back rights, there was no change to stock-based compensation expense for the impact of the previously disclosed restatement of the 2016 consolidated financial statements. As of March 31, 2020 , 253,203 shares had vested, 200,297 shares were forfeited, and the remaining 93,500 shares vested (as to 80% ) in February 2020. In October 2018, we granted 464,888 PSUs with certain financial targets. These PSUs will become eligible to vest at 75% on the second month following achievement of certain performance targets by December 31, 2020, with the remaining 25% of the PSUs to vest on the first anniversary of the initial vesting date, subject to continued service vesting requirements. None of these PSUs were vested as of March 31, 2020 . In April 2019, we granted 346,453 PSUs with certain financial targets. These PSUs will become eligible to vest at 75% on the second month following achievement of certain performance targets by December 31, 2021, with the remaining 25% of the PSUs to vest on the first anniversary of the initial vesting date, subject to continued service vesting requirements. None of these PSUs were vested as of March 31, 2020 . In December 2019, we granted 375,000 PSUs with certain market performance-based targets to be achieved between December 2019 and December 2023. One-third of each tranche of these PSUs will become eligible to vest on each of the three anniversaries of the date the performance-based target is achieved, subject to continued service vesting requirements. The grant date fair values of each tranche of these PSUs were estimated to be $4.59 , $4.06 and $3.59 . None of these PSUs were vested as of March 31, 2020 . The following table summarizes our stock award activities and related information: Number of Shares (thousands) Weighted-Average Grant Date Fair Value per Share Weighted-Average Remaining Vesting Term (years) Nonvested as of December 31, 2019 6,148 $ 6.59 Granted 132 5.75 Released (486 ) 6.42 Canceled (511 ) 6.67 Nonvested as of March 31, 2020 5,283 $ 6.58 1.75 The aggregate fair value of stock awards released as of the respective vesting dates was $3.4 million and $3.8 million for the three months ended March 31, 2020 and 2019 , respectively.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed using the weighted average number of common shares outstanding for the period. Diluted net loss per share is computed using the weighted average number of common shares outstanding for the period plus potential dilutive common shares, including stock options, RSUs and employee stock purchase rights, unless the potential common shares are anti-dilutive. Since we had net losses during the three months ended March 31, 2020 and 2019 , none of the potential dilutive common shares were included in the computation of diluted shares for these periods, as inclusion of such shares would have been anti-dilutive. Basic and diluted net loss per share are calculated as follows (in thousands, except per share amounts): Three Months Ended March 31, 2020 2019 Basic and diluted net loss per share Numerator: Net loss $ (297 ) $ (12,272 ) Denominator: Weighted-average shares outstanding - basic 78,061 74,809 Weighted-average shares outstanding - diluted 78,061 74,809 Net loss per share: Basic and diluted $ 0.00 $ (0.16 ) The following table presents common shares related to potentially dilutive shares excluded from the calculation of diluted net loss per share as their effect would have been anti-dilutive (in thousands): Three Months Ended March 31, 2020 2019 Stock options, restricted stock units and employee stock purchase rights 8,182 9,997

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We recorded income tax expense of $0.3 million and $0.5 million for the three months ended March 31, 2020 and 2019 , respectively, which primarily consisted of foreign taxes. Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the carrying amounts of existing assets and liabilities in the financial statements and their respective tax bases using tax rates expected to be in effect during the years in which the basis differences reverse. We believe it is more likely than not that our federal and state net deferred tax assets will not be fully realized. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of our deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. A valuation allowance is recorded for loss carryforwards and other deferred tax assets where it is more likely than not that such deferred tax assets will not be realized. Accordingly, we continue to maintain a valuation allowance against all of our U.S. and certain foreign net deferred tax assets as of March 31, 2020 . We will continue to maintain a full valuation allowance against our net federal, state, and certain foreign deferred tax assets until there is sufficient evidence to support the recoverability of our deferred tax assets. We had $4.3 million of unrecognized tax benefits as of March 31, 2020. We do not anticipate a material change to our unrecognized tax benefits over the next twelve months. Unrecognized tax benefits may change during the next twelve months for items that arise in the ordinary course of business. Accrued interest and penalties related to unrecognized tax benefits are recognized as part of our provision for income taxes in our condensed consolidated statements of operations. We are subject to taxation in the United States, various states, and several foreign jurisdictions. Because we have net operating loss and credit carryforwards, there are open statutes of limitations in which federal, state, and foreign taxing authorities may examine our tax returns for all years from 2005 through the current period. We are not currently under examination by any taxing authorities.

Geographic Information

Geographic Information	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Geographic Information	Geographic Information The following table depicts the disaggregation of revenue by geographic region based on the ship to location of our customers and is consistent with how we evaluate our financial performance (in thousands): Three Months Ended March 31, 2020 2019 Americas $ 25,438 $ 21,133 Japan 17,641 13,152 Asia Pacific, excluding Japan 4,882 8,776 EMEA 5,803 7,229 Total revenue $ 53,764 $ 50,290 The following table is a summary of our long-lived assets which include property and equipment, net and operating lease right-of-use assets based on the physical location of the assets (in thousands): March 31, December 31, United States $ 34,483 $ 35,964 Japan 2,393 2,689 Other 1,926 2,017 Total $ 38,802 $ 40,670

Revenue Revenue

Revenue Revenue	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Contract Balances The following table reflects contract balances with customers (in thousands): March 31, 2020 December 31, 2019 Accounts receivable, net $ 42,862 $ 53,566 Deferred revenue, current 62,718 62,233 Deferred revenue, non-current 38,560 38,931 We receive payments from customers based upon billing cycles. Invoice payment terms usually range from 30 to 90 days. Accounts receivable are recorded when the right to consideration becomes unconditional. Contract assets include amounts related to our contractual right to consideration for performance obligations not yet billed and are included in prepaid and other current assets in the condensed consolidated balance sheets. The amount was immaterial as of March 31, 2020 and December 31, 2019. Deferred revenue primarily consists of amounts that have been invoiced but not yet been recognized as revenue and consists of performance obligations pertaining to support and subscription services. During the three months ended March 31, 2020 and 2019 , we recognized revenue of $21.3 million and $23.7 million , respectively, related to deferred revenues at the beginning of the respective periods. Deferred Contract Acquisition Costs In connection with the adoption of ASC 340-40, we capitalize certain contract acquisition costs consisting of incremental sales commissions incurred to obtain customer contracts. Deferred commissions related to product revenues are recognized upon transfer of control to customers. Deferred commissions related to services revenue are recognized as the related performance obligations are met. Deferred commissions that will be recognized during the succeeding 12-month period are recorded as prepaid expenses and other current assets, and the remaining portion is recorded as other non-current assets. Amortization of deferred commissions is included in sales and marketing expense. Deferred contract acquisition costs were $8.5 million and $9.5 million as of March 31, 2020 and December 31, 2019 , respectively, and the related amortization amount was $1.7 million and $2.0 million for the three months ended March 31, 2020 and 2019 , respectively. We had no impairment loss in relation to the costs capitalized and no asset impairment charges related to contract assets during the three months ended March 31, 2020 and 2019 . Remaining Performance Obligations Remaining performance obligations represent contracted revenues that are non-cancellable and have not yet been recognized due to unsatisfied or partially satisfied performance obligations, which include deferred revenues and amounts that will be invoiced and recognized as revenues in future periods. We expect to recognize revenue on the remaining performance obligations as follows (in thousands): March 31, 2020 Within 1 year $ 62,718 Next 2 to 3 years 29,673 Thereafter 8,887 Total $ 101,278

Description of Business and S_2

Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of A10 Networks, Inc. and its subsidiaries after elimination of all intercompany accounts and transactions. We have prepared the accompanying unaudited condensed consolidated financial statements pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC” or the “Commission”). As permitted under these rules and regulations, we have condensed or omitted certain financial information and footnote disclosures we normally include in our annual consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The unaudited condensed consolidated balance sheet as of December 31, 2019 has been derived from our audited financial statements, which are included in our 2019 Annual Report on Form 10-K for the year ended December 31, 2019 on file with the SEC (the “2019 Annual Report”). These financial statements have been prepared on the same basis as our annual financial statements and, in management’s opinion, reflect all adjustments consisting only of normal recurring adjustments that are necessary for a fair presentation of our financial information. Our interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the financial statements and accompanying notes thereto in the 2019 Annual Report.
Use of Estimates	Use of Estimates
Concentration of Credit Risk and Significant Customers	Concentration of Credit Risk and Significant Customers Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents, marketable securities and accounts receivable. Our cash, cash equivalents and marketable securities are held and invested in high-credit quality financial instruments by recognized financial institutions and are subject to minimum credit risk. Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing periodic credit evaluations based on a number of factors, including past transaction experience, evaluation of credit history and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable.
Recently Adopted Accounting Guidance/Recent Accounting Pronouncements Not Yet Effective	Recent Adopted Accounting Pronouncements Effective January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), as amended, using a modified retrospective approach, with certain exceptions allowed. The standard amends the guidance for measuring and recording credit losses on financial assets measured at amortized cost by replacing the incurred-loss model with an expected-loss model. This new standard also requires that credit losses related to available-for-sale debt securities be recorded as an allowance through net income rather than by reducing the carrying amount under the current, other-than-temporary-impairment model. The adoption of ASU 2016-13 did not have a significant impact on the Company’s Condensed Consolidated Financial Statements. Effective January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820 - Changes to the Disclosure Requirements for the Fair Value Measurement) . Entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The guidance is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The new guidance did not have a significant impact on the Company’s Condensed Consolidated Financial Statements. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350)—Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 simplifies the accounting for goodwill impairments by eliminating the requirement to compare the implied fair value of goodwill with its carrying amount as part of step two of the goodwill impairment test referenced in Accounting Standards Codification (“ASC”) 350, Intangibles - Goodwill and Other (“ASC 350”). As a result, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value. However, the impairment loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 is effective for annual reporting periods beginning after December 15, 2019, including any interim impairment tests within those annual periods, with early application permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. In January 2020, the Company adopted ASU 2017-04, and the adoption had no impact on our condensed consolidated financial statements. The Company will perform future goodwill impairment tests according to ASU 2017-04.
Deferred Contract Acquisition Costs	Deferred Contract Acquisition Costs In connection with the adoption of ASC 340-40, we capitalize certain contract acquisition costs consisting of incremental sales commissions incurred to obtain customer contracts. Deferred commissions related to product revenues are recognized upon transfer of control to customers. Deferred commissions related to services revenue are recognized as the related performance obligations are met. Deferred commissions that will be recognized during the succeeding 12-month period are recorded as prepaid expenses and other current assets, and the remaining portion is recorded as other non-current assets. Amortization of deferred commissions is included in sales and marketing expense.

Description of Business and S_3

Description of Business and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Revenue as Percentage of Total Revenue	Three Months Ended Customers 2020 2019 Customer A (a distribution channel partner) * 13% Customer B (a distribution channel partner) 17% * Customer C (a distribution channel partner) 16% * * represents less than 10% of total revenue

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Assets And Liabilities,	The table below presents the Company’s right-of-use assets and lease liabilities as of March 31, 2020 (in thousands): March 31, 2020 Operating leases Right-of-use assets: Other non-current assets $ 31,340 Total right-of-use assets $ 31,340 Lease liabilities: Accrued liabilities $ 4,716 Other non-current liabilities 26,871 Total operating lease liabilities $ 31,587
Lease Payments	The aggregate future lease payments for non-cancelable operating leases as of March 31, 2020 were as follows (in thousands): Remainder of 2020 $ 4,230 2021 5,519 2022 4,659 2023 4,414 2024 4,518 Thereafter 11,773 Total lease payments 35,113 Less: imputed interest (3,526 ) Present value of lease liabilities $ 31,587
Lease Costs	Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Operating lease costs $ 1,777 $ 893 Short-term lease costs 158 137 Total lease costs $ 1,935 $ 1,030 Average lease terms and discount rates for the Company’s operating leases were as follows (in thousands): March 31, 2020 Weighted-average remaining term (years) 6.87 Weighted-average discount rate 3.14 % Supplemental cash flow information for the Company’s operating leases was as follows (in thousands): Three Months Ended March 31, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,665

Marketable Securities and Fai_2

Marketable Securities and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Available-for-sale Securities	Marketable securities, classified as available-for-sale, consisted of the following (in thousands): March 31, 2020 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 9,049 $ 6 $ — $ 9,055 $ 10,548 $ 10 $ — $ 10,558 Corporate securities 51,041 53 (163 ) 50,931 51,745 207 (1 ) 51,951 U.S. Treasury and agency securities 6,716 64 — 6,780 9,222 3 — 9,225 Commercial paper 500 — — 500 500 — — 500 Asset-backed securities 10,003 16 (12 ) 10,007 11,914 32 — 11,946 Total $ 77,309 $ 139 $ (175 ) $ 77,273 $ 83,929 $ 252 $ (1 ) $ 84,180
Schedule of Cost and Estimated Fair Values of Available-for-sale Securities by Contractual Maturity	The following table summarizes the cost and estimated fair value of marketable securities based on stated effective maturities as of March 31, 2020 (in thousands): Amortized Cost Fair Value Less than 1 year $ 34,906 $ 34,902 Mature in 1 - 3 years 42,403 42,371 Total $ 77,309 $ 77,273
Schedule of gross unrealized losses	Marketable securities in an unrealized loss position consisted of the following (in thousands): Less Than 12 Months 12 Months or More Total March 31, 2020 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Certificates of deposit $ — $ — $ 2,375 $ (1 ) $ 2,375 $ (1 ) Corporate securities 15,751 (68 ) 13,359 (94 ) 29,110 (162 ) Asset-backed securities 1,372 (2 ) 3,045 (10 ) 4,417 (12 ) Total $ 17,123 $ (70 ) $ 18,779 $ (105 ) $ 35,902 $ (175 ) Less Than 12 Months 12 Months or More Total December 31, 2019 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate securities $ 2,996 $ (1 ) $ — $ — $ 2,996 $ (1 )
Schedule of Cash, Cash Equivalents and Available-for-sale Investments Measured at Fair Value on Recurring Basis	The following is a summary of our cash, cash equivalents and marketable securities measured at fair value on a recurring basis (in thousands): March 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 48,175 $ — $ — $ 48,175 $ 35,546 $ — $ — $ 35,546 Cash equivalents 17,458 — — 17,458 10,196 — — 10,196 Certificates of deposit — 9,055 — 9,055 — 10,558 — 10,558 Corporate securities — 50,931 — 50,931 — 51,951 — 51,951 U.S. Treasury and agency securities — 6,780 — 6,780 — 9,225 — 9,225 Commercial paper — 500 — 500 — 500 — 500 Asset-backed securities — 10,007 — 10,007 — 11,946 — 11,946 Total $ 65,633 $ 77,273 $ — $ 142,906 $ 45,742 $ 84,180 $ — $ 129,922

Condensed Consolidated Financ_2

Condensed Consolidated Financial Statement Details (Tables)	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): March 31, December 31, Raw materials $ 9,829 $ 9,495 Finished goods 10,935 12,889 Total inventory $ 20,764 $ 22,384
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): March 31, 2020 December 31, 2019 Prepaid expenses $ 4,514 $ 6,163 Deferred contract acquisition costs 5,302 6,231 Other 2,702 2,673 Total prepaid expenses and other current assets $ 12,518 $ 15,067
Schedule of Property and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): Useful Life March 31, December 31, (in years) Equipment 1 - 5 $ 23,483 $ 22,702 Software 1 - 3 765 726 Furniture and fixtures 1 - 7 652 459 Leasehold improvements Lease term 5,438 5,440 Construction in process 48 — Property and equipment, gross 30,386 29,327 Less: accumulated depreciation (22,924 ) (21,671 ) Property and equipment, net $ 7,462 $ 7,656
Schedule of Acquired Intangible Assets	Purchased intangible assets, net, consisted of the following (in thousands): March 31, 2020 December 31, 2019 Cost Accumulated Amortization Net Cost Accumulated Amortization Net Developed technology $ 5,050 $ (3,788 ) $ 1,262 $ 5,050 $ (3,535 ) $ 1,515 Patents 2,936 (2,254 ) $ 682 2,936 (2,146 ) 790 Total intangible assets $ 7,986 $ (6,042 ) $ 1,944 $ 7,986 $ (5,681 ) $ 2,305
Schedule of Future Amortization Expense for Purchased Finite-lived Intangible Assets	Future amortization expense for purchased intangible assets as of March 31, 2020 is as follows (in thousands): Fiscal Year Remainder of 2020 $ 1,082 2021 862 Total $ 1,944
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): March 31, December 31, Accrued compensation and benefits $ 10,121 $ 12,227 Accrued tax liabilities 2,987 4,354 Lease liability 4,716 5,109 Other 6,419 6,066 Total accrued liabilities $ 24,243 $ 27,756
Schedule of Deferred Revenue	Deferred revenue consisted of the following (in thousands): March 31, December 31, Deferred revenue: Products $ 6,456 $ 6,593 Services 94,822 94,571 Total deferred revenue 101,278 101,164 Less: current portion (62,718 ) (62,233 ) Non-current portion $ 38,560 $ 38,931

Equity Incentive Plans and St_2

Equity Incentive Plans and Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock-based Compensation	A summary of our stock-based compensation expense is as follows (in thousands): Three Months Ended March 31, 2020 2019 Stock-based compensation by type of award: Stock options $ 110 $ 184 Stock awards 2,682 3,474 Employee stock purchase rights 248 238 $ 3,040 $ 3,896 Stock-based compensation by category of expense: Cost of revenue $ 325 $ 324 Sales and marketing 764 1,321 Research and development 1,006 1,331 General and administrative 945 920 $ 3,040 $ 3,896
Summary of Activity under Stock Option Plans	The following tables summarize our stock option activities and related information: Number of Shares (thousands) Weighted-Average Exercise Price per Share Weighted-Average Remaining Contractual Term (years) Aggregate Intrinsic Value (thousands) Outstanding as of December 31, 2019 3,702 $ 5.57 Granted — — Exercised (644 ) 4.37 Canceled (171 ) 6.29 Outstanding as of March 31, 2020 2,887 5.80 3.01 $ 3,195 Vested and exercisable as of March 31, 2020 2,810 $ 5.73 2.90 $ 3,194
Summary of Restricted Stock Units Activity	The following table summarizes our stock award activities and related information: Number of Shares (thousands) Weighted-Average Grant Date Fair Value per Share Weighted-Average Remaining Vesting Term (years) Nonvested as of December 31, 2019 6,148 $ 6.59 Granted 132 5.75 Released (486 ) 6.42 Canceled (511 ) 6.67 Nonvested as of March 31, 2020 5,283 $ 6.58 1.75

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	Basic and diluted net loss per share are calculated as follows (in thousands, except per share amounts): Three Months Ended March 31, 2020 2019 Basic and diluted net loss per share Numerator: Net loss $ (297 ) $ (12,272 ) Denominator: Weighted-average shares outstanding - basic 78,061 74,809 Weighted-average shares outstanding - diluted 78,061 74,809 Net loss per share: Basic and diluted $ 0.00 $ (0.16 )
Summary of Anti-dilutive Shares	The following table presents common shares related to potentially dilutive shares excluded from the calculation of diluted net loss per share as their effect would have been anti-dilutive (in thousands): Three Months Ended March 31, 2020 2019 Stock options, restricted stock units and employee stock purchase rights 8,182 9,997

Geographic Information (Tables)

Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Schedule of Total Revenue Based on Customer's Location	The following table depicts the disaggregation of revenue by geographic region based on the ship to location of our customers and is consistent with how we evaluate our financial performance (in thousands): Three Months Ended March 31, 2020 2019 Americas $ 25,438 $ 21,133 Japan 17,641 13,152 Asia Pacific, excluding Japan 4,882 8,776 EMEA 5,803 7,229 Total revenue $ 53,764 $ 50,290
Long-lived Assets by Geographic Areas	The following table is a summary of our long-lived assets which include property and equipment, net and operating lease right-of-use assets based on the physical location of the assets (in thousands): March 31, December 31, United States $ 34,483 $ 35,964 Japan 2,393 2,689 Other 1,926 2,017 Total $ 38,802 $ 40,670

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset and Liability	The following table reflects contract balances with customers (in thousands): March 31, 2020 December 31, 2019 Accounts receivable, net $ 42,862 $ 53,566 Deferred revenue, current 62,718 62,233 Deferred revenue, non-current 38,560 38,931
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	We expect to recognize revenue on the remaining performance obligations as follows (in thousands): March 31, 2020 Within 1 year $ 62,718 Next 2 to 3 years 29,673 Thereafter 8,887 Total $ 101,278

Description of Business and S_4

Description of Business and Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)solution
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Software Based Advanced Solutions | solution	6
ROU asset	$ 31,340
Present value of lease liabilities	$ 31,587

Description of Business and S_5

Description of Business and Summary of Significant Accounting Policies - Concentration Risk (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Customer A | Revenue
Entity Wide Revenue Major Customer [Line Items]
Percentage representation of significant customers (percent)		13.00%
Customer A | Accounts Receivable
Entity Wide Revenue Major Customer [Line Items]
Percentage representation of significant customers (percent)	21.00%		17.00%
Customer B | Revenue
Entity Wide Revenue Major Customer [Line Items]
Percentage representation of significant customers (percent)	17.00%
Customer B | Accounts Receivable
Entity Wide Revenue Major Customer [Line Items]
Percentage representation of significant customers (percent)	20.00%		12.00%
Customer C | Revenue
Entity Wide Revenue Major Customer [Line Items]
Percentage representation of significant customers (percent)	16.00%

Leases - Assets and Liabilities

Leases - Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Total right-of-use assets	$ 31,340
Accrued liabilities	4,716	$ 5,109
Other non-current liabilities	26,871
Total operating lease liabilities	$ 31,587

Leases - Lease Liabilities (Det

Leases - Lease Liabilities (Details) $ in Thousands	Mar. 31, 2020USD ($)
Leases [Abstract]
Remainder of 2020	$ 4,230
2021	5,519
2022	4,659
2023	4,414
2024	4,518
Thereafter	11,773
Total lease payments	35,113
Less: imputed interest	(3,526)
Present value of lease liabilities	$ 31,587

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease costs	$ 1,777	$ 893
Short-term lease costs	158	137
Total lease costs	$ 1,935	$ 1,030
Weighted-average remaining term (years)	6 years 10 months 13 days
Weighted-average discount rate	3.14%
Operating cash flows from operating leases	$ 1,665

Marketable Securities and Fai_3

Marketable Securities and Fair Value Measurements - Estimate of Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 77,309	$ 83,929
Gross Unrealized Gains	139	252
Gross Unrealized Losses	(175)	(1)
Fair Value	77,273	84,180
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,049	10,548
Gross Unrealized Gains	6	10
Gross Unrealized Losses	0	0
Fair Value	9,055	10,558
Corporate securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	51,041	51,745
Gross Unrealized Gains	53	207
Gross Unrealized Losses	(163)	(1)
Fair Value	50,931	51,951
U.S. Treasury and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,716	9,222
Gross Unrealized Gains	64	3
Gross Unrealized Losses	0	0
Fair Value	6,780	9,225
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	500	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	500	500
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,003	11,914
Gross Unrealized Gains	16	32
Gross Unrealized Losses	(12)	0
Fair Value	$ 10,007	$ 11,946

Marketable Securities and Fai_4

Marketable Securities and Fair Value Measurements - Contractual Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized Cost
Less than 1 year	$ 34,906
Mature in 1 - 3 years	42,403
Amortized Cost	77,309	$ 83,929
Fair Value
Less than 1 year	34,902
Mature in 1 - 3 years	42,371
Fair Value	$ 77,273	$ 84,180

Marketable Securities and Fai_5

Marketable Securities and Fair Value Measurements - Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value
Less Than 12 Months	$ 17,123
12 Months or More	18,779
Total	35,902
Gross Unrealized Losses
Less Than 12 Months	(70)
12 Months or More	(105)
Total	(175)
Certificates of deposit
Fair Value
Less Than 12 Months	0
12 Months or More	2,375
Total	2,375
Gross Unrealized Losses
Less Than 12 Months	0
12 Months or More	(1)
Total	(1)
Corporate securities
Fair Value
Less Than 12 Months	15,751	$ 2,996
12 Months or More	13,359	0
Total	29,110	2,996
Gross Unrealized Losses
Less Than 12 Months	(68)	(1)
12 Months or More	(94)	0
Total	(162)	$ (1)
Asset-backed securities
Fair Value
Less Than 12 Months	1,372
12 Months or More	3,045
Total	4,417
Gross Unrealized Losses
Less Than 12 Months	(2)
12 Months or More	(10)
Total	$ (12)

Marketable Securities and Fai_6

Marketable Securities and Fair Value Measurements - Schedule of Fair Value of Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial Assets
Marketable Securities	$ 77,273	$ 84,180
Total	142,906	129,922
Level 1
Financial Assets
Total	65,633	45,742
Level 2
Financial Assets
Total	77,273	84,180
Cash
Financial Assets
Cash and Cash Equivalents	48,175	35,546
Cash | Level 1
Financial Assets
Cash and Cash Equivalents	48,175	35,546
Cash equivalents
Financial Assets
Cash and Cash Equivalents	17,458	10,196
Cash equivalents | Level 1
Financial Assets
Cash and Cash Equivalents	17,458	10,196
Certificates of deposit
Financial Assets
Marketable Securities	9,055	10,558
Certificates of deposit | Level 2
Financial Assets
Marketable Securities	9,055	10,558
Corporate securities
Financial Assets
Marketable Securities	50,931	51,951
Corporate securities | Level 2
Financial Assets
Marketable Securities	50,931	51,951
U.S. Treasury and agency securities
Financial Assets
Marketable Securities	6,780	9,225
U.S. Treasury and agency securities | Level 2
Financial Assets
Marketable Securities	6,780	9,225
Commercial paper
Financial Assets
Marketable Securities	500	500
Commercial paper | Level 2
Financial Assets
Marketable Securities	500	500
Asset-backed securities
Financial Assets
Marketable Securities	10,007	11,946
Asset-backed securities | Level 2
Financial Assets
Marketable Securities	$ 10,007	$ 11,946

Condensed Consolidated Financ_3

Condensed Consolidated Financial Statement Details - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 9,829	$ 9,495
Finished goods	10,935	12,889
Total inventory	$ 20,764	$ 22,384

Condensed Consolidated Financ_4

Condensed Consolidated Financial Statement Details - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Prepaid expenses	$ 4,514	$ 6,163
Deferred contract acquisition costs	5,302	6,231
Other	2,702	2,673
Total prepaid expenses and other current assets	$ 12,518	$ 15,067

Condensed Consolidated Financ_5

Condensed Consolidated Financial Statement Details - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 30,386	$ 29,327
Less: accumulated depreciation	(22,924)	(21,671)
Property and equipment, net	7,462	7,656
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	23,483	22,702
Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	765	726
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	652	459
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	5,438	5,440
Construction in process
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 48	$ 0
Minimum | Equipment
Property Plant And Equipment [Line Items]
Useful life	1 year
Minimum | Software
Property Plant And Equipment [Line Items]
Useful life	1 year
Minimum | Furniture and fixtures
Property Plant And Equipment [Line Items]
Useful life	1 year
Minimum | Leasehold improvements
Property Plant And Equipment [Line Items]
Useful life	2 years
Maximum | Equipment
Property Plant And Equipment [Line Items]
Useful life	3 years
Maximum | Software
Property Plant And Equipment [Line Items]
Useful life	3 years
Maximum | Furniture and fixtures
Property Plant And Equipment [Line Items]
Useful life	3 years
Maximum | Leasehold improvements
Property Plant And Equipment [Line Items]
Useful life	8 years

Condensed Consolidated Financ_6

Condensed Consolidated Financial Statement Details - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1.3	$ 1.2
Amortization expense related to intangible assets	$ 0.4	$ 0.7

Condensed Consolidated Financ_7

Condensed Consolidated Financial Statement Details - Purchased Intangible Assets, net (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 7,986	$ 7,986
Accumulated Amortization	(6,042)	(5,681)
Total	1,944	2,305
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	5,050	5,050
Accumulated Amortization	(3,788)	(3,535)
Total	1,262	1,515
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	2,936	2,936
Accumulated Amortization	(2,254)	(2,146)
Total	$ 682	$ 790

Condensed Consolidated Financ_8

Condensed Consolidated Financial Statement Details - Future Amortization Expense of Acquired Intangibles (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Remainder of 2020	$ 1,082
2020	862
Total	$ 1,944	$ 2,305

Condensed Consolidated Financ_9

Condensed Consolidated Financial Statement Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 10,121	$ 12,227
Accrued tax liabilities	2,987	4,354
Lease liability	4,716	5,109
Other	6,419	6,066
Total accrued liabilities	$ 24,243	$ 27,756

Condensed Consolidated Finan_10

Condensed Consolidated Financial Statement Details - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 101,278	$ 101,164
Less: current portion	(62,718)	(62,233)
Non-current portion	38,560	38,931
Products
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	6,456	6,593
Services
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 94,822	$ 94,571

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 1.6	$ 1

Equity Incentive Plans and St_3

Equity Incentive Plans and Stock-Based Compensation - 2014 Equity Incentive Plan/ESPP (Details) - USD ($) $ in Millions	Jan. 01, 2019	Sep. 30, 2018	Jun. 10, 2015	Oct. 31, 2018	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised					$ 1.2	$ 1.1
2014 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant					15,166,550
2014 Stock Incentive Plan | Prior Common Stock Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding shares of common stock	5.00%
Additional shares authorized for future issuance (in shares)	3,879,002
2014 Stock Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares reserved for future issuance (in shares)			8,000,000
Percentage of outstanding shares of common stock			5.00%
2014 Employee Stock Purchase Plan | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of eligible compensation		15.00%
Offering period		24 months
Amended 2014 Employee Stock Purchase Plan | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of eligible compensation				10.00%
Offering period				6 months
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant					2,402,820,000

Equity Incentive Plans and St_4

Equity Incentive Plans and Stock-Based Compensation - Schedule of Stock-based Compensation Awards Granted under Stock Option Plan in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 3,040	$ 3,896
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	325	324
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	764	1,321
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,006	1,331
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	945	920
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	110	184
Stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	2,682	3,474
Employee stock purchase rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 248	$ 238

Equity Incentive Plans and St_5

Equity Incentive Plans and Stock-Based Compensation - Stock-based Compensation/Stock Repurchase Program (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total compensation expense related to unvested awards granted, not yet recognized	$ 24.3
Total compensation expense related to unvested awards granted, not yet recognized weighted-average period for recognition (in years)	2 years 7 months 20 days

Equity Incentive Plans and St_6

Equity Incentive Plans and Stock-Based Compensation - Summary of Activity under Stock Option Plans (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Number of Shares (thousands)
Outstanding options, Beginning balance (in shares)	3,702
Granted (in shares)	0
Exercised (in shares)	(644)
Canceled (in shares)	(171)
Outstanding options, Ending balance (in shares)	2,887
Vested and exercisable (in shares)	2,810
Weighted-Average Exercise Price per Share
Beginning balance (in dollars per share)	$ 5.57
Granted (in dollars per share)	0
Exercised (in dollars per share)	4.37
Canceled (in dollars per share)	6.29
Ending balance (in dollars per share)	5.80
Vested and exercisable at end of period (in dollars per share)	$ 5.73
Weighted-average remaining contractual term (in years)	3 years 2 days
Weighted average remaining contractual term, Vested and exercisable at end of period (in years)	2 years 10 months 24 days
Aggregate Intrinsic Value	$ 3,195
Aggregate Intrinsic Value, Vested and exercisable at end of period	$ 3,194
Closing price (in dollars per share)	$ 6.21
Intrinsic value of options exercised	$ 1,200	$ 1,100

Equity Incentive Plans and St_7

Equity Incentive Plans and Stock-Based Compensation - Information About Stock Options (Details) - shares	1 Months Ended				3 Months Ended
	Feb. 29, 2020	Apr. 30, 2019	Oct. 31, 2018	Feb. 29, 2016	Mar. 31, 2020
Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		346,000
PSUs, February 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				547,000
Actual performance vesting percentage				80.00%
Vested in period (in shares)	93,500				253,203
Forfeited in period (in shares)					200,297
Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			464,888
Vested in period (in shares)					0
Share-based Compensation Award, Tranche One [Member] | Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		75.00%
Share-based Compensation Award, Tranche One [Member] | PSUs, February 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage					80.00%
Share-based Compensation Award, Tranche One [Member] | Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			75.00%
Share-based Compensation Award, Tranche Two [Member] | Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		25.00%
Share-based Compensation Award, Tranche Two [Member] | Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			25.00%

Equity Incentive Plans and St_8

Equity Incentive Plans and Stock-Based Compensation - Summary of RSU activity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			3 Months Ended
	Dec. 31, 2019	Apr. 30, 2019	Oct. 31, 2018	Mar. 31, 2020	Mar. 31, 2019
Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)		346,000
Performance Stock Units, December 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)	375,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested at beginning of period (in shares)				6,148,000
Granted (in shares)				132,000
Released (in shares)				(486,000)
Canceled (in shares)				(511,000)
Unvested at end of period (in shares)	6,148,000			5,283,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested at beginning of period (in dollars per share)				$ 6.59
Granted (in dollars per share)				5.75
Released (in dollars per share)				6.42
Canceled (in dollars per share)				6.67
Unvested at ending of period (in dollars per share)	$ 6.59			$ 6.58
Weighted-Average Remaining Vesting Term (years)				1 year 9 months
Fair value of released awards				$ 3.4	$ 3.8
Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)			464,888
Released (in shares)				0
Share-based Compensation Award, Tranche One [Member] | Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Award vesting percentage		75.00%
Share-based Compensation Award, Tranche One [Member] | Performance Stock Units, December 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested at beginning of period (in dollars per share)				$ 4.59
Unvested at ending of period (in dollars per share)	4.59
Share-based Compensation Award, Tranche One [Member] | Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Award vesting percentage			75.00%
Share-based Compensation Award, Tranche Two [Member] | Performance Stock Units, April 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Award vesting percentage		25.00%
Share-based Compensation Award, Tranche Two [Member] | Performance Stock Units, December 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested at beginning of period (in dollars per share)				4.06
Unvested at ending of period (in dollars per share)	4.06
Share-based Compensation Award, Tranche Two [Member] | Performance Stock Units, October 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Award vesting percentage			25.00%
Share-based Compensation Award, Tranche Three [Member] | Performance Stock Units, December 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested at beginning of period (in dollars per share)				$ 3.59
Unvested at ending of period (in dollars per share)	$ 3.59

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Outstanding Shares of Common Stock Equivalents (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock options, restricted stock units and employee stock purchase rights
Earnings Per Share Diluted [Line Items]
Anti-dilutive securities excluded from computation of diluted net income per share	8,182	9,997

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (297)	$ (12,272)
Weighted-average shares outstanding, Basic (in shares)	78,061	74,809
Weighted-average shares outstanding, Diluted (in shares)	78,061	74,809
Net loss per share, Basic and Diluted (in dollars per share)	$ 0	$ (0.16)

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 319	$ 517
Unrecognized tax benefits	$ 4,300		$ 4,200

Geographic Information - Schedu

Geographic Information - Schedule of Total Revenue Based on Customer's Location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 53,764	$ 50,290
Americas
Segment Reporting Information [Line Items]
Total revenue	25,438	21,133
Japan
Segment Reporting Information [Line Items]
Total revenue	17,641	13,152
Asia Pacific, excluding Japan
Segment Reporting Information [Line Items]
Total revenue	4,882	8,776
EMEA
Segment Reporting Information [Line Items]
Total revenue	$ 5,803	$ 7,229

Geographic Information - Long L

Geographic Information - Long Lived Assets By Geographic Area (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 38,802	$ 40,670
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	34,483	35,964
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	2,393	2,689
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,926	$ 2,017

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue	$ 21,300,000	$ 23,700,000
Deferred contract acquisition costs	8,500,000		$ 9,500,000
Deferred contract acquisition costs, amortization	1,700,000		$ 2,000,000
Asset impairment charges for contract assets	0
Deferred Sales Commissions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Impairment loss of contract acquisition costs	$ 0

Revenue - Contract Balances (De

Revenue - Contract Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 42,862	$ 53,566
Deferred revenue	62,718	62,233
Deferred revenue, non-current	$ 38,560	$ 38,931

Revenue - Remaining Performance

Revenue - Remaining Performance Obligations (Details) $ in Thousands	Mar. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 101,278
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 62,718
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 29,673
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 8,887
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period